Studies on the role of the membrane in bacterial cell wall biosynthesis will involve two cell wall defective mutants of gram positive bacteria. One of the mutants, a non-reverting L-form, has been shown to contain membrane proteins which differ from the "wild type" and further biochemical and physical characterization of these proteins will be made. Characterization of the level of lysylphosphatidyl glycerol in the membrane and its relationship to osmotic stability will be continued. The components of the cell wall of a mutant of Staphylococcus aureus H$ which has been shown to be deficient in teichoic acid, will be studied by biochemical and physical techniques at various sta@es of autolysis.